Use a namespace of `/` for mirage
Use a namespace of `/` for mirage

Passing no namespace is causing routes not be to recognized after the
move to ember-cli 2.7

jrjohnson/frontend,thecoolestguy/frontend,gabycampagna/frontend,ilios/frontend,thecoolestguy/frontend,stopfstedt/frontend,stopfstedt/frontend,jrjohnson/frontend,gabycampagna/frontend,djvoa12/frontend,dartajax/frontend,gboushey/frontend,gboushey/frontend,djvoa12/frontend,dartajax/frontend,ilios/frontend